This disclosure relates generally to a sheet feeder, and more particularly concerns sheet feeder having a reversing retard roll utilizing an integral torque limiting slip clutch having a reversing bias.
In a typical electrophotographic printing process, a photoconductive member is charged to a substantially uniform potential so as to sensitize the surface thereof. The charged portion of the photoconductive member is exposed to a light to selectively dissipate the charges thereon in the irradiated areas. This records an electrostatic latent image on the photoconductive member corresponding to the informational areas contained within the original document. After the electrostatic latent image is recorded on the photoconductive member, the latent image is developed by bringing a developer material into contact therewith. Generally, the developer material comprises toner particles adhering triboelectrically to carrier granules. The toner particles are attracted from the carrier granules to the latent image forming a toner powder image on the photoconductive member. The toner powder image is then transferred from the photoconductive member to a copy sheet. The toner particles are heated to permanently affix the powder image to the copy sheet.
In a commercial printing machine of the foregoing type, a sheet misfeed or multi-fed sheets can seriously impair the operation of the machine. It is advantageous in many of today's machines to provide for the in seriatim feeding of sheets from the top of the stack. Many devices have been developed to attempt to alleviate problems associated with feeding sheets and prevent multi-fed sheets. The present disclosure improves over past systems by providing a simple integral device to separate multi-feeds quickly and effectively.